Document and Entity Information - shares	6 Months Ended
	Apr. 30, 2020	May 20, 2020
Cover [Abstract]
Document Transition Report	false
Title of 12(b) Security	Common Stock($0.01 par value)
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Type	10-Q
Document Period End Date	Apr. 30, 2020
Amendment Flag	false
Entity File Number	000-19807
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Trading Symbol	SNPS
Entity Registrant Name	SYNOPSYS, INC.
Entity Address, Address Line One	690 EAST MIDDLEFIELD ROAD
Entity Address, City or Town	MOUNTAIN VIEW
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94043
City Area Code	650
Local Phone Number	584-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Entity Central Index Key	0000883241
Current Fiscal Year End Date	--10-31
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		150,788,707
Entity Tax Identification Number	56-1546236
Security Exchange Name	NASDAQ